Anchor tag jumping to hash not working

[f]

I've read various posts on this subject and think I understand the usual points of failure. I find that my two product thumbnail images, under the "This Click'n'Pick Set Consists Of The Following 2 Products" heading, are clickable, but do not take me to the named \[code\]<div>\[/code\] element further down the page. Instead, they cause navigation to http://www.premierrange.co.uk/#bundle_product_anchor_448, for example. I see this both in Chrome (18.0.1025.33 beta) and Firefox (10.0.1) on Linux.http://www.premierrange.co.uk/index.php?main_page=clicknpick&groups_id=2&chosen_0=243&chosen_1=448So for example there's an anchor targeting '#bundle_product_anchor_243':\[code\]<a href="http://stackoverflow.com/questions/9407738/#bundle_product_anchor_243" title="Click here to jump to the 70cm Truly Curved Black Glass Curved Cooker Hood H77-7B"> <img src="http://www.premierrange.co.uk/thumbnailer.php?filename=images/H77-700.jpg&height=100" alt="70cm Truly Curved Black Glass Curved Cooker Hood H77-7B"></a>\[/code\]This targets the \[code\]<div>\[/code\] further down the page:\[code\]<div class="productSeparator" id="bundle_product_anchor_243"> <h1>Product number 1 in this bundle of 2 products</h1></div>\[/code\]I've also tried making the \[code\]<h1>\[/code\] inside the target \[code\]<div>\[/code\] be the target instead, in case the target must be an inline element rather than a div, but nothing seems to work.The \[code\]<div>\[/code\] containing the badly behaving \[code\]<a>\[/code\] is completely closed by the time the \[code\]<div>\[/code\] containing the target element appears in the document. I don't think there's a problem with the target element not being defined at the point in time the \[code\]<a>\[/code\] is parsed by the browser.Manually adding "#bundle_product_anchor_448" to the URL does work.I am aware that the page fails HTML validation on a large number of points, due to a large number of factors that I'm not going to be able to address easily. I'd have thought this basic 'jump to a named element' functionality should work regardless. The page is completely functional other than this little navigation quirk.Anyone got any clues?